The invention relates to a hollow rocker-arm shaft for internal combustion engines and a method of manufacturing such a rocker-arm shaft which has at least two longitudinal passages for carrying control and lubricating fluid.
A hollow rocker-arm shaft is known from EP 0 259 106 B1, FIGS. 9, 10 wherein a longitudinal internal web forms separate passages for supplying lubricating oil to valve actuation means and for supplying control oil to control means.
The interior of the hollow rocker-arm shaft is sub-divided by longitudinal webs into at least three fluid-carrying chambers. The longitudinal webs are firmly connected to the rocker-arm shaft.
It is the principal object of the present invention to optimize, in terms of production efforts and expenditures, the manufacture of rocker-arm shafts which include at least two passages and consist preferably of sheet steel.